Foscenvivint

Neuronal differentiation and neurite growth are essential processes in nervous system development and are regulated by several factors. Although all-trans retinoic acid (ATRA) has been shown to mediate the differentiation of mouse neuroblastoma cells via the activation of several pathways, including Wnt/β-catenin signaling, the mechanism remains unclear. The pyruvate kinase, muscle (PKM) plays an important role in the glycolysis of neuroblastoma cells and regulates the Wnt signaling pathway in various cancer cells. In this study, we hypothesized that the Wnt/PKM axis regulates the differentiation of neuroblastoma cells (Neuro-2a and N1E-115). To test this hypothesis, we used inhibitors and activators of the Wnt/β-catenin and glycolytic pathways in ATRA-induced differentiated Neuro-2a and N1E-115 cells and established cell lines with silenced or a mutant replacement of Pkm. Western blot and qPCR showed that ATRA treatment activated the Wnt signaling pathway and inhibited PKM-mediated glycolysis. The oxygen consumption rate (indicating oxidative phosphorylation) significantly increased, whereas the extracellular acidification rate (indicating glycolysis) significantly decreased during differentiation; these effects were reversed upon PKM inhibition. The Wnt inhibitor ICG-001 and PKM activator ML-265 inhibited ATRA-induced Neuro-2a and N1E-115 differentiation, whereas RNA interference-mediated Pkm silencing promoted Neuro-2a and N1E-115 differentiation, which was reversed by PKM overexpression. Treatment with the Wnt activator kenpaullone promoted Neuro-2a and N1E-115 differentiation, which was reversed by ML-265 administration. These results indicate that Wnt/β-catenin signaling promotes Neuro-2a and N1E-115 differentiation by inhibiting PKM-mediated glycolysis during ATRA-induced differentiation. These findings may provide a new theoretical basis for the role of glycolysis in nerve differentiation.

Proliferation and transdifferentiation of the retinal pigment epithelium (RPE) are hallmarks of proliferative vitreoretinopathy (PVR); however, the critical regulators of this process remain to be elucidated. Here, we investigated the role of tenascin-C in PVR development. In vitro, exposure of human ARPE-19 (hRPE) cells to TGF-β2 increased tenascin-C expression. Tenascin-C was shown to be involved in TGF-β2-induced transdifferentiation of hRPE cells, which was inhibited by pretreatment with tenascin-C siRNA. In PVR mouse models, a marked increase in the expression of tenascin-C mRNA and protein was observed. Additionally, immunofluorescence analysis demonstrated a dramatic increase in the colocalization of tenascin-C with RPE65 or α-smooth muscle actin(α-SMA) in the epiretinal membranes of patients with PVR. There was also abundant expression of integrin αV and β-catenin in the PVR membranes. ICG-001, a β-catenin inhibitor, efficiently attenuated PVR progression in a PVR animal model. These findings suggest that tenascin-C is secreted by transdifferentiated RPE cells and promotes the development of PVR via the integrin αV and β-catenin pathways. Therefore, tenascin-C could be a potential therapeutic target for the inhibition of epiretinal membrane development associated with PVR.